The 15th edition of this annual educational seminar, considered by many experts as one of the pillars of medical training in pharmacovigilance, focuses on medical knowledge in the diagnosis and management of Adverse Drug Reactions (ADRs). A medical approach is needed for the identification, labelling and understanding of ADR mechanisms. It can also improve the evaluation of the probability that a medicinal product may have played a role in the occurrence of an adverse event. This is particularly useful for the first 2 or 3 cases of serious reactions occurring during clinical trials when important decisions must be taken regarding a drug under development. The medical approach presented during this seminar is mainly based on the conclusions of international or national consensus meetings on adverse drug reactions.